JP4183451B2 - Control device for cooling system - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a control device for a cooling system including, for example, a low-temperature showcase installed in a supermarket or the like and a refrigerator that supplies refrigerant to the low-temperature showcase.
[0002]
[Prior art]
Conventionally, a plurality of low-temperature showcases such as freezer / refrigerated showcases are installed in a store such as a supermarket, and are used to display and sell food while being frozen or refrigerated. In this case, the refrigerant in each low temperature showcase is circulated and supplied from a refrigerator installed outside the store (such as a machine room). In this case, depending on the store, products of different manufacturers may be used for the low temperature showcase and the refrigerator, and the refrigerant circuit of the cooling system may be configured.
[0003]
On the other hand, in recent years, in stores such as supermarkets, a measure for reducing power consumption in the cooling system is emphasized from the viewpoint of tackling environmental problems and reducing energy costs. In order to reduce the power consumption, it is important to improve the operating efficiency of the low-temperature showcase and the refrigerator itself. It is also possible to reduce power consumption.
[0004]
Therefore, for example, in Japanese Patent Application Laid-Open No. 9-217974, an inverter type refrigerator is targeted, and a proposal has been made to reduce power consumption by setting a low-pressure side pressure set value of a refrigerant circuit and an inverter frequency based on the set value. . This low-pressure side pressure set value is a value for stopping and operating the compressor of the refrigerator, and is generally a set value suitable for the situation where the most cooling capacity is required in summer. Therefore, in situations where high cooling capacity is not required, such as in winter, it is possible to reduce power consumption by reducing the cooling capacity.
[0005]
In order to realize this, it is necessary to determine that the current cooling capacity has a margin so as not to cause poor cooling of the displayed food even if the cooling capacity is lowered. Therefore, in the above publication, the operating rate of the low temperature showcase is used as a basic evaluation index, and the cooling capacity of the entire cooling system is evaluated.
[0006]
[Problems to be solved by the invention]
However, the cooling capacity of the low temperature showcase is greatly affected by the operating environment of the low temperature showcase. In other words, the cooling capacity of the entire cooling system depends on the performance of the low-temperature showcase and the refrigerator, and is fixed, but the cooling state in the refrigerator of the low-temperature showcase depends on the temperature around the low-temperature showcase and the refrigerator. Affected and constantly changing. Therefore, in order to determine the marginal cooling capacity of the entire cooling system, it is necessary to determine the cooling state in the storage in consideration of the influence received from the operating environment.
[0007]
In this case, the operating rate in the above publication can also be an index for determining how much cooling capacity is available when the inside temperature of the low-temperature showcase is maintained at a set value. That's not true. In addition, when only the operating rate is used as a determination index, the operating rate is affected by the operating environment as described above, and in order to achieve effective reduction of power consumption by performing quick and detailed control. It must be said that it is insufficient.
[0008]
The present invention has been made to solve the conventional technical problem, and provides a control device that can more effectively reduce power consumption in a cooling system.
[0009]
[Means for Solving the Problems]
The control device of the present invention is a cooling system composed of a low-temperature showcase and a refrigerator that supplies refrigerant to the low-temperature showcase, and registration locations according to environmental conditions obtained by a combination of store temperature, store temperature, and time. The database is constructed by registering the control data for controlling the operation of the refrigerator at each registered location, and the judgment result data on the quality of the cooling state in the low-temperature showcase storage, and the temperature inside the store, outside the store Check the registration status of the data at the registration location of the database from the environmental condition data related to the operating conditions including temperature and time. Based on the registered judgment result data, the registered control data can be rewritten or rewritten. It is characterized by being output to .
[0010]
In addition to the above, the control device for the cooling system of the invention of claim 2 assumes that the current store interior temperature and store exterior temperature will continue thereafter, and is registered in the database registration location corresponding to the environmental conditions. The control data is output as it is or after being rewritten according to the determination result data at the present time .
[0011]
In addition to the above inventions, the control device for the cooling system of the invention of claim 3 controls the control data in a direction to reduce power consumption in the refrigerator while ensuring cooling of the inside of the low temperature showcase based on the determination result data. It is characterized by rewriting .
[0012]
In addition to the above inventions, the control device for the cooling system of the invention of claim 4 is characterized in that the control data is a low-pressure side pressure set value for controlling the operation of the refrigerator .
[0013]
Controller of the cooling system of the invention of claim 5, in addition to the above inventions, and generates a determination result data on the basis of the deviation temperature for the interior temperature target value of the low-temperature showcase, the database that corresponds to the environmental conditions It is characterized in that it is registered at a registration location .
[0014]
In the present invention, since the operation of the refrigerator is controlled in consideration of the operating environment conditions in addition to the quality of the cooling state in the refrigerator of the low-temperature showcase, in order to reduce the power consumption of the refrigerator, more prompt and detailed Control becomes possible. This makes it possible to effectively reduce the power consumption of the entire cooling system while ensuring the minimum cooling capacity necessary to maintain the cooling of the interior of the low temperature showcase.
[0015]
In particular, in order to reduce the power consumption of the refrigerator, the low pressure side pressure set value is output as control data, so that it is possible to cope with refrigerators other than the inverter type. Further, it is possible to make a more direct determination by using the deviation temperature inside the low temperature showcase instead of the operation rate as the determination result data as the cooling state determination index. In addition, by using store temperature, store temperature and time as operating environment conditions, in addition to the season, the store opening and closing, lighting and lighting, product replenishment and night cover installation, etc. and customer visits It becomes possible to respond accurately to the situation.
[0016]
Further, according determined by environmental conditions as control data results data to register to build a database, environmental conditions at the present time is assumed to be continued subsequently, as the control data of the environmental conditions, or the determination result data By rewriting and outputting according to the above, it is possible to predict the transition of the operating environment and to fine-tune control that quickly follows it.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a longitudinal side view of a low-temperature showcase 1 as an embodiment to which the present invention is applied, FIG. 2 is a diagram illustrating a piping configuration of a cooling system RS in a supermarket where the low-temperature showcase 1 is installed, and FIG. It is a control block diagram of other cooling system RS.
[0018]
The low-temperature showcase 1 of the embodiment is a vertical open showcase, and is composed of a heat insulating wall 32 having a substantially U-shaped cross section and side plates (not shown) attached to both sides of the heat insulating wall 32 at the installation site. Yes. An outer layer partition plate 34 and an inner layer partition plate 36 are attached to the inner side of the heat insulating wall 32 with a space therebetween, and the space between the heat insulating wall 32 and the outer layer partition plate 34 is between the outer layer duct 37 and the inner and outer layer partition plates 36, 34. Is an inner layer duct 38, and the inner side of the inner layer partition plate 36 is a storage chamber 39 (inside the box).
[0019]
A plurality of shelves 41 are built in the storage chamber 39, and fluorescent lamps 40 are placed in the front of the lower surface of each shelf 41, the ceiling of the storage chamber 39, and in the basket 37. It is attached. A deck pan 42 is attached to the bottom of the storage chamber 39, and the bottom of the deck pan 42 is a bottom duct 43 communicating with both the ducts 37 and 38. A fan case 44 containing a blower 45 is installed in the bottom duct 43. In addition, an evaporator 46 is provided vertically at a lower portion in the inner layer duct 38 located behind the storage chamber 39.
[0020]
At the upper edge of the front opening 51 of the storage chamber 39, an outer layer discharge port 52 and an inner layer discharge port 53 are juxtaposed in the front-rear direction, the outer layer discharge port 52 being the outer layer duct 37 and the inner layer discharge port 53 being the inner layer duct 38, respectively. Communicate. A suction port 54 is formed at the lower edge of the opening 51 and communicates with the bottom duct 43.
[0021]
When the blower 45 in the fan case 44 is operated, the air in the bottom duct 43 is blown out toward the rear inner and outer layer ducts 37 and 38, and is blown up as it is in the outer layer duct 37 and the inner layer duct 38. In this case, the air is blown up after exchanging heat with the evaporator 46 and blown out from the inner and outer layer discharge ports 52 and 53 on the upper edge of the opening 51 toward the suction port 54 on the lower edge.
[0022]
As a result, an inner cold air curtain and an outer air curtain that protects the inner cool air curtain are formed in the opening 51 of the storage chamber 39, and intrusion of outside air from the opening 51 is prevented or suppressed. A part of the air curtain circulates in the storage chamber 39 and the storage chamber 39 is cooled. When the store is closed, the opening 51 is closed with a night cover (not shown).
[0023]
These cold air and the like return from the suction port 54 to the bottom duct 43 and are sucked into the blower 45 again. Further, a defrosting heater 67 is attached to the evaporator 46, and heat is generated to melt the frost on the evaporator 46.
[0024]
Next, in FIG. 2, what is indicated by 1a... Is a low-temperature showcase (a refrigerated case for fruits and vegetables) that stores and displays fruits and vegetables (commodities), and is arranged in parallel. Reference numeral 1b... Denotes a low temperature showcase (fresh temperature ice temperature case) for storing and displaying fresh fish (commodities).
[0025]
Each of the low-temperature showcases 1a, 1b,... Is installed along the wall surface in the supermarket store as shown in FIG. On the other hand, 11 and 12 are separately installed refrigeration refrigerators and ice temperature refrigerators installed (separated) in a machine room 13 configured outside the store. These low-temperature showcases 1a,. ... and the refrigerators 11 and 12 constitute the cooling system RS of the present invention.
[0026]
Each of the refrigerators 11 and 12 is constituted by a compressor and a condenser (not shown), and the inlet side of the evaporator 46 of the low temperature showcase 1a (refrigerated case). And the outlet side of the evaporator 46 is connected in parallel to the gas refrigerant pipe 18 of the refrigeration refrigerator 11, respectively.
[0027]
Further, the inlet side of the evaporator 46... Of the low temperature showcase 1 b (ice temperature case)... Is connected in parallel to the liquid refrigerant pipe 22 of the ice temperature refrigerator 12 through the electromagnetic valve 19 and the expansion valve 21. At the same time, the outlet side of the evaporator 46 is connected in parallel to the gas refrigerant pipe 23 of the ice temperature refrigerator 12.
[0028]
The control device of each low-temperature showcase 1a, 1b controls the opening and closing of the electromagnetic valves 14 and 19 based on the temperature of the cold air blown into the storage chamber 39 or there, and supplies the refrigerant to the evaporator 46 to supply the refrigerant into the storage chamber 39. Cool down. That is, the upper limit temperature and the lower limit temperature are set above and below the target value (set temperature) of the storage chamber 39, and the solenoid valves 14 and 19 are opened at the upper limit temperature and the ON-OFF control is closed at the lower limit temperature. . Thereby, the temperature of the storage chamber 39 (inside the cabinet) is brought close to the target value as an average, but a deviation temperature is generated between the target value and the actual temperature of the storage chamber 39 depending on the cooling capacity and the surrounding environment.
[0029]
On the other hand, the compressors of the refrigerators 11 and 12 are operated when any one of the electromagnetic valves 14 and 19 is open, but the electromagnetic valve 14 is used in all the low temperature showcases 1a. Alternatively, if 19 is closed, it is stopped. In this case, specifically, the low pressure side pressure set value of the refrigerant circuit is used, and the control device of each of the refrigerators 11 and 12 causes the pressure on the low pressure side of the refrigerant circuit to be closed by closing all the electromagnetic valves 14 or 19. When the pressure is lowered to the low pressure side set value, the compressor is stopped. Then, if the solenoid valve 14 or 19 of any of the low temperature showcases 1a or 1b is opened and the low pressure side pressure becomes higher than the low pressure side pressure set value (in this case, a predetermined hysteresis is provided), the compression is performed again. The machine will be started.
[0030]
Next, the operation of the control device (hereinafter referred to as a controller) 10 for reducing the power consumption of the cooling system RS according to the present invention will be described with reference to FIG. The controller 10 is constituted by a general-purpose microcomputer having a memory and a clock function (indicated by 20) in which a database 15 described later is constructed, and between each low-temperature showcase 1a ... and the refrigerator 11, and Each of the low-temperature showcases 1b... And the refrigerator 12 is interposed to exchange data.
[0031]
In this case, the controller 10 and 10 receive the above-described deviation temperature and in-store temperature of the storage room 39 (inside the store) from the low-temperature showcases 1a. Further, the store outside temperatures are input from the refrigerators 11 and 12, respectively. Then, the low pressure side pressure set values are output as control data from the controllers 10 and 10 to the refrigerators 11 and 12, respectively.
[0032]
Next, a specific operation of the controller 10 will be described. Hereinafter, the controller 10 interposed between the low temperature showcase 1a ... and the refrigerator 11 will be described, but the controller 10 between the low temperature showcase 1b ... and the refrigerator 12 is the same. And
[0033]
First, the database 15 described above is constructed in the memory of the controller 10. In this database 15, data registration locations are classified based on the three conditions of the in-store temperature, the outside temperature, and the time zone, which are indicators for determining operating environment conditions, and are registered as discrete data classified into a plurality of stages. The The discretization rule in this case is
In-store temperature Ti (° C.): The range of 0 ° C. to + 35 ° C. is classified into 8 stages in 5 deg increments (actually, the average value per hour is adopted).
Out-of-store temperature To (° C.): The range of −5 ° C. to + 40 ° C. is classified into 10 stages in 5 deg increments (actually an average value per hour is adopted).
Time zone t: Classified into 24 stages in units of 1 hour.
In total, there are 1920 registered locations.
[0034]
The store interior temperature and store exterior temperature are operating environment conditions that are influenced by the natural environment. In addition, the cooling state of the low-temperature showcase 1a is affected not only by the natural environment, but also by the frequency of food in and out by store staff and customers, lighting off for energy-saving purposes when the store is closed, blockage by night covers, etc. It becomes possible to judge by the belt. In addition, regarding the calculation of the average value of the deviation temperature which will be described later, the time point including the calculation start time is set as the time zone. For example, when the average deviation temperature is calculated from the deviation temperature for 60 minutes from 3:40 pm to 4:40 pm, the time zone is treated as 3:00 pm. When the in-store temperature is lower than 0 ° C., it is treated as 0 ° C., when it is higher than + 35 ° C., it is treated as + 35 ° C., and when the outside temperature is lower than −5 ° C., it is treated as −5 ° C. If it is higher than + 40 ° C., it is handled as + 40 ° C.
[0035]
Then, the controller 10 stores the low pressure side pressure set value Ps (PaG) of the refrigerator 11 as control data and data of the determination result of the cooling state of the storage chamber 39 of the low temperature showcase 1a (determination result data) at each registration location of the database 15. ) Is registered as shown in FIG.
[0036]
The determination result data is obtained by calculating an average deviation temperature Te (deg) per fixed time (actually one hour) from the deviation temperatures sent from the low temperature showcases 1a. The determination is made based on whether the average deviation temperature Te is equal to or higher than a preset threshold value A. When the average deviation temperature Te of all the low-temperature showcases 1a... Connected to the controller 10 is not equal to or higher than the threshold value A, the determination result data is “good” and even one unit has the threshold value A. When there is the low temperature showcase 1a as described above, the determination result data is registered as “No” in the registration location of the store temperature, store temperature, and time zone.
[0037]
This threshold A is a value for judging whether the average deviation temperature Te is good or not, and is set to a value that can maintain a sufficiently good cooling state in the storage chamber 39 of the low temperature showcase 1a.
[0038]
Next, an example of actual control with the above configuration will be described. The controller 10 adjusts the low pressure side pressure set value of the refrigerator 11 based on the database 15 described above. The adjustment of the low-pressure side pressure set value of the refrigerator 11 is executed at a predetermined cycle, and hereinafter, an example of adjusting at a one-hour cycle will be described.
[0039]
First, a default value is registered in advance as an initial value of the low pressure side pressure set value Ps, which is control data, in all the registration locations of the database 15. Therefore, when the low temperature showcase 1a... And the refrigerator 11 are initially installed in the supermarket, the low pressure side pressure set value Ps is set to a default value. This default value is the value of the environment that requires the most cooling capacity in summer, and the adjustment of the low pressure side pressure setting value Ps performed for the purpose of reducing power consumption thereafter is more than the default value. The adjustment is performed in the direction of increasing, and the adjustment does not lower the default value.
[0040]
On the other hand, the initial value registration is not performed for the determination result data regarding the determination result of the quality of the cooling state of the storage chamber 39 of the low temperature showcase 1a, that is, the data for determining the quality of the average deviation temperature Te described above. That is, after the operation of the low-temperature showcase 1a... And the refrigerator 11 is started, the determination result data obtained from the actual measurement is gradually registered by the annual operation through the change of seasons.
[0041]
Here, among the operating environment conditions described above, the in-store temperature Ti and the out-of-store temperature To can be said to be indicators that do not change significantly in about one hour. Therefore, in the actual control of the controller 10, assuming that the in-store temperature Ti and the out-of-store temperature To in the past one hour continue in the subsequent one hour, the in-store temperature Ti and the out-of-store temperature To are 1 Check the registration status of the data at the corresponding registration location after time.
[0042]
And when the determination result (determination result data) of the cooling state is not registered in the registration location (hereinafter referred to as D1), the low pressure side pressure setting is used for the operation in the time zone (time zone after 1 hour). The value Ps is set as a default value, registered as control data in the registration location D1, and the control data is output to the refrigerator 11. The refrigerator 11 controls the start / stop of the compressor as described above based on the low pressure side pressure set value Ps transmitted from the controller 10.
[0043]
Note that the determination result data obtained by actual operation in the time zone (one hour later) corresponds to the actual in-store temperature Ti and the outside temperature To (and the time zone) in the time zone. It is registered at the registration location of the database 15.
[0044]
On the other hand, when the determination result (determination result data) of the cooling state is registered in the registration location D1, the control differs depending on the quality of the determination result. That is, when the determination result of “No” is registered in the registration location D1, the controller 10 keeps the low pressure side pressure setting value Ps as the value registered in the registration location D1, or the registered low pressure side. When the pressure set value Ps is higher than the default value, the pressure set value Ps is rewritten to a value reduced by a constant value (PaG), and the rewritten value is output to the refrigerator 11 as control data. In the refrigerator 11, the stop and start of the compressor are controlled based on the low pressure side pressure set value Ps transmitted from the controller 10 as described above. At this time, the low pressure side pressure set value Ps is set to a low value. The low-pressure side pressure set value Ps at which the compressor is started / stopped is lowered, and the cooling capacity is improved correspondingly.
[0045]
That is, at the same in-store temperature Ti and out-of-store temperature To, the registered state of the database 15 corresponding to the next one hour time zone has a poor cooling state as a result of the previous operation in the operating environment, and the determination result is “ If registered as “No”, the cooling capacity of the refrigerator 11 is maintained or improved to improve the cooling state of the storage chamber 39 of the low temperature showcase 1a.
[0046]
On the contrary, when the determination result of “good” is registered in the registration location D1, the controller 10 determines that the cooling capacity is sufficient, and the low-pressure side pressure set value Ps is obtained from the value registered in the registration location D1. Is also rewritten to a value increased by a certain value (PaG), and the rewritten value is output to the refrigerator 11 as control data. The refrigerator 11 controls the stop and start of the compressor based on the low pressure side pressure set value Ps transmitted from the controller 10 as described above. At this time, the low pressure side pressure set value Ps is set to a high value. The low-pressure side pressure set value Ps at which the compressor is started / stopped is increased, and accordingly, the cooling capacity is lowered and the power consumption is also reduced.
[0047]
That is, at the same in-store temperature Ti and out-of-store temperature To, the registered state of the database 15 corresponding to the next one hour time zone has a good cooling state as a result of the previous operation in the operation environment, and the determination result is “good”. ”Is registered, it is determined that the cooling capacity of the refrigerator 11 has a margin, and the cooling capacity is reduced, while maintaining the cooling state of the storage chamber 39 of the low temperature showcase 1a. The power consumption of the refrigerator 11 is reduced.
[0048]
When it is determined that the cooling capacity of the cooling system RS is sufficient by such control, the cooling capacity of the refrigerator 11 is lowered to reduce power consumption, and the storage room 39 of the low temperature showcase 1a. The average deviation temperature Te is maintained in the vicinity of the threshold value A.
[0049]
In addition, the driving | running environment conditions shown in the Example are not limited to it. In the embodiment, the low-pressure side pressure set value of the refrigerator is adjusted as control data. However, this is not limited, and any control factor related to the cooling capacity and power consumption of the cooling system can be used. Furthermore, in the embodiment, the low-pressure side pressure set value is adjusted in a one-hour cycle. is there.
[0050]
【The invention's effect】
As described above in detail, according to the present invention, since the operation of the refrigerator is controlled in consideration of the operating environment conditions in addition to the quality of the cooling state in the low temperature showcase, the power consumption of the refrigerator is reduced. In addition, quicker and finer control is possible. This makes it possible to effectively reduce the power consumption of the entire cooling system while ensuring the minimum cooling capacity necessary to maintain the cooling of the interior of the low temperature showcase.
[0051]
In particular, in order to reduce the power consumption of the refrigerator, the low pressure side pressure set value is output as control data, so that it is possible to cope with refrigerators other than the inverter type. Further, it is possible to make a more direct determination by using the deviation temperature inside the low temperature showcase instead of the operation rate as the determination result data as the cooling state determination index. In addition, by using store temperature, store temperature and time as operating environment conditions, in addition to the season, the store opening and closing, lighting and lighting, product replenishment and night cover installation, etc. and customer visits It becomes possible to respond accurately to the situation.
[0052]
Also, it is assumed that the database is constructed by registering control data and judgment result data for each environmental condition, and that the current environmental condition continues, and the control data of the environmental condition is used as it is or judgment result data By rewriting and outputting according to the above, it is possible to predict the transition of the operating environment and to fine-tune control that quickly follows it.
[Brief description of the drawings]
FIG. 1 is a longitudinal side view of an embodiment of a low-temperature showcase constituting a cooling system to which the present invention is applied.
FIG. 2 is a diagram illustrating a piping configuration of a supermarket where the low temperature showcase of FIG. 1 is installed.
FIG. 3 is a control block diagram of the cooling system of the present invention.
FIG. 4 is a diagram illustrating a controller database of the cooling system of the present invention.
[Explanation of symbols]
1a, 1b Low temperature showcase 10 Controller (control device)
11, 12 Refrigerator 14, 19 Solenoid valve 15 Database

Claims (5)

In a cooling system comprising a low temperature showcase and a refrigerator that supplies refrigerant to the low temperature showcase,
Control data for controlling the operation of the refrigerator at each registered location, having a registered location for each environmental condition obtained by a combination of the store temperature, store temperature and time, and the cooling state of the low temperature showcase A database is built by registering judgment result data on the quality of
The registered control data is checked based on the registered determination result data by checking the registration status of the data at the registration location of the database from the environmental condition data regarding the operating conditions including the in-store temperature, the outside temperature and the time. Is output as it is or rewritten to the refrigerator . Assuming that the current store temperature and store outside temperature will continue thereafter, the control data registered in the registration location of the database corresponding to the environmental condition is used as it is or the determination result at the current time 2. The cooling system control device according to claim 1, wherein the control device is rewritten and output in accordance with data . 3. The control data according to claim 1, wherein the control data is rewritten in a direction of reducing power consumption in the refrigerator while ensuring cooling of the inside of the low-temperature showcase based on the determination result data. Control device for cooling system. 4. The cooling system control device according to claim 1, wherein the control data is a low pressure side pressure set value for controlling the operation of the refrigerator . 3. The determination result data is generated on the basis of a deviation temperature with respect to an internal temperature target value of the low-temperature showcase, and is registered in a registration location of the database corresponding to the environmental condition. 5. A control device for a cooling system according to claim 3 or claim 4 .

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